Hemiparesis is a condition typified by unilateral weakness or partial loss or impairment of voluntary movement of the entire left or right side of the body. Hemiplegia, in its most severe form, is a complete paralysis on one side of the body. Wheelchair mobility for persons with hemiparesis or hemiplegia presents particular challenges because conventional manual wheelchairs typically require the user be able to apply power bilaterally to the wheelchair in order for the user to self-power and steer the wheelchair. Similarly, persons suffering from a loss of both an arm and a leg (on the same side or on opposite sides), or loss of control of both an arm and a leg, are typically unable to propel and control a conventional manual wheelchair.
Using conventional manual wheelchairs such persons, even though they may have good control and strength on one side of their body (or good use of an arm and a leg on opposite sides of their body), may be forced to rely on caretakers or others to push them whenever they need to move to another location. This, of course, limits their ability to live on their own, or even to safely spend significant time alone.
One wheelchair alternative to persons suffering from hemiparesis or hemiplegia is to acquire a powered wheelchair that can be operated by one hand. Such wheelchairs, however, are quite expensive, and do not provide the user with the physical activity associated with self-powered wheelchairs. Moreover, powered wheelchairs are more prone to malfunction or simply running down their power source, and they are much more difficult to transport between distant locations in a car, or the like.
For example, U.S. Pat. No. 4,241,932, to Hartmann, which is hereby incorporated by reference in its entirety, discloses a wheelchair steering apparatus that requires a user to twist or turn his or her ankle to steer the wheelchair. Twisting the ankle can be very hard and uncomfortable, and over time the twisting may cause injury to the ankle. The foot turntable mounts to the chair's original footrest greatly restricting the turning radius making it hard to maneuver in tight areas and not possible to turn 180 degrees in one spot. The rigid mounted turntable and tie rods, which require tools to remove, restrict the ability of an assistant to push and steer the chair. The Hartmann device also interferes with the caster full range of motion.
In U.S. Pat. No. 3,810,658, to Weimer, Sr., which is hereby incorporated by reference, a steerable wheelchair apparatus is disclosed, with a tie bar connecting the chair's front casters together. This construction would not allow for tight turns. Also, the disclosed device would interfere with the user (or an assistant) from making tight turns, for example, in narrow hallways, or the like. The Weimer, Sr., chair would also be difficult for many users because the turning device is operated from the user's upper leg. Another disadvantage is that this system is not easily removable thus hampering said chair with steering restrictions.
There remains a need for a steerable device for a manual wheelchair that does not require the user to twist their ankle to steer, that allows the user to execute a tight turn in a confined area, and that is readily removable. An improved steering device will provide improved independence, particularly for persons with hemiparesis, hemiplegia, and the like, who may otherwise require others to push them, or to obtain and use an expensive and cumbersome electric wheelchair. In addition, devices in accordance with the present invention allow the user to steer without having to turn or twist their foot and ankle, and in some embodiments may be attached or removed without requiring any tools and/or may be rotated out of the way when not in use.